FORT STEWART, GA. — Her heart thumping under 100 pounds of combat gear, medic Pfc. Joaida Cruz scrambled across a clearing, dropped to a watchful crouch — her weapon at the ready — then raced ahead into a kneel, ran again and dropped to the prone position before darting ahead and exiting the field, her face damp with sweat.

The tactical movement drill was not a field exercise but part of a massive three-year Army experiment involving 500 soldiers of both genders, eight installations and 31 hard-core combat tasks like dragging a wounded buddy to safety or loading 65-pound anti-tank missiles.

Army leadership plans to use the research to inform the creation of a physical aptitude test, or series of tests, that could drastically alter how soldiers are assigned to jobs.

Officials say the overall effort, dubbed Soldier 2020, has a simple goal: to put the right candidate in the right military occupational specialty, irrespective of gender.

Army officials likened the notional test to the Armed Services Vocational Aptitude Battery, a multiple-choice cognitive test often administered to potential enlistees in high school by Military Entrance Processing Command to predict their success in various occupations.

The tests would likely be applied to combat arms jobs, in which physicality is a must, but not necessarily limited to those jobs. The Army’s research thus far has focused on armor, combat engineering, field artillery and infantry.

Leaders are keeping an open mind about how this test would be implemented and what exercises will be part of the test. Researchers know for sure the test would have to be feasible to administer with little equipment or training, similar to the PT test, so it will likely be comprised of exercises adapted to mimic soldier tasks.

When eventually implemented, these tests could make or break a soldier’s career. A soldier whose heart is set on infantry but can’t complete the test, for example, might find himself or herself in a cubicle instead.

“There are probably soldiers in these MOSs right now that don’t meet these standards, but we’d never have a way of determining it,” said Maj. Gen. Mike Murray, whose 3rd Infantry Division at Fort Stewart contributed to the study. “There will be a set of tests that will determine whether a soldier is capable of performing the physical tasks associated with that MOS from a physical standpoint. ... We’re interested in what’s right for the Army, but we’re equally interested in what’s right for that soldier.”

Murray said he believed soldiers would perform better knowing the soldier next to him had passed the same test he did.

“We’ve always had soldiers who carried a heavier load,” Murray said. “This will enable all soldiers to be able to pick up the machine gun and carry it for 12 miles or pick up the .50 caliber machine gun and mount it on a tank. You don’t have to rely on a certain small group of soldiers to do the heavy tasks or the hard tasks. Every soldier in that unit should be qualified to do that.”

There are many issues to work out, issues that could have significant impacts on soldier careers. Some of the major questions leaders will have to wrestle with:

■ Will these tests be administered to recruits before they in-process or later?

■ Will soldiers already serving in the MOSs have to take the test?

■ What about soldiers hoping to reclassify into a job that requires a test?

These are all policy questions researchers say top Army leaders will decide after the study ends in September 2015.

“We’re not predetermining anything through the process,” said Maj. Allison Hamilton, of the Soldier 2020 Task Force. “I have not heard any discussions saying this is what we’re going to do because we don’t know.”